气温大大低于冰点时最好是呆在室内，除非你迫于生计而不得不外出。 It's best to keep in while the temperature is so for below freezing point, unless you have to go out to earn your living.
维持生计；在学校里修得额外的学分 Gain a living; gain extra credits in school.
埃里克以当簿记员来维持生计，且利用周末当舞会伴奏赚些外快。 Eric earned his bread and butter as a bookkeeper, but added a little jam by working with a dance band on weekends.